Check-weighing machine



Feb. 10, 1953 M. KNOBEL ET AL CHECK-WEIGHING MACHINE 7 Sheets-Sheet 1Filed Oct. 24, 1951 vaw jN;OR. Wa/naa P/{J dMQW INV May i670 feb 10,1953 M. KNOBEL ET AL CHECK-WEIGHING MACHINE 7 Sheets-Sheet 2 Filed Oct.24, 1951 IN V ENTOR. MG'X f fia y 721mm; p/7 dwdrc/ d! Jan, cL-mmi Feb.10, 1953 Filed 001;. 24, 1951 M. KNOBEL ET AL CHECK-WEIGHING MACHINE 7Sheets-Sheet 5 INVENTOR. MCIX Mace/ BY Zoom: Zjfi/flward Patented Feb.10, 1953 UNITED STATES PATENT OFFICE CHECK-WEIGHING MACHINE ApplicationOctober 24, 1951, Serial No. 252,834

15 Claims.

This invention relates to a check-weighing machine.

The invention has for an object to provide a novel and improved andrapidly operating checkweighing apparatus in which provision is made fordetermining the deviation in the weight of an article from apredetermined weight and for ascertaining the average algebraicdeviation of a plurality or group of the weighed articles from apredetermined weight and for indicating and preferably graphicallyrecording the average algebraic deviation from such predetermined weightof the group thus check weighed.

With this general object in view and such others as may hereinafterappear, the invention consists in the check-weighing apparatus and inthe various structures, arrangements, and combinations of partshereinafter described and particularly defined in the claims at the endof this specification.

In the drawings, Fig. l is a plan view of the present check-weighingapparatus shown operatively connected to a gross-weight weighing machinefor forming weighed loads in successive cartons; Fig. 2 is a sideelevation, partly in cross section, of the present check weigher; Figs.3, 4, and are cross-sectional views taken on the lines 33, 44, and 55respectively of Fig. 2; Fig. 6 is a side elevation of thecarrier-driving mechanism as viewed from the left in Fig. 1; Fig. '7 isa side elevation of a portion of the driving mechanism as viewed fromthe right in Fig. 1; Fig. 8 is a side elevation of portions of thegrossweight weighing machine shown in Fig. l embodying mechanism foreffecting corrections in the formation of the weighed loads in responseto determinations of average algebraic deviations beyond definiteamounts forming predetermined weight of a plurality of weighed loads;Fig. 9 is a cross-sectional detail view of the correcting mechanismshown in Fig. 8; Fig. 10 is a plan view of the correcting mechanism;Fig. 11 is a side elevation of a net-weight weighing machine embodyingsimilar correcting mechanism and operatively connected to the presentcheck weigher; Fig. 12 is a cross-sectional view of a volumetric filleralso embodying similar correcting mechanism operatively connected to thepresent check weigher; Fig. 13 is a side elevation of thevolumecorrecting mechanism shown in Fig. 12; Fig. 14 is a detail View,partly in cross section, of the correcting mechanism as seen from theline Ill-l 4 of Fig. 13; Fig. 15 is a side elevation of a modified formof indicating and recording mechanism; Fig. 16 is a cross-sectional Viewtaken on the line Iii-l6 of Fig. 15; and Fig. 17 is a diagrammatic Viewof the mechanism shown in Fig. 15.

In general, in the present check-weighing apparatus provision is madefor determining the variation in the weight of the article or load froma predetermined weight, preferably by a weighing element includingrapidly operating, relatively stifi spring means, and provision is alsomade for ascertaining the average algebraic deviation of a plurality orgroup of weighed articles from the predetermined weight and forindicating such average algebraic deviation. The machine embodies novelpneumatically operated mechanism of a highly sensitive nature whichcooperates with the weighing element-to rapidly and accurately translatethe minute movement of the weighing element under the influence of theexcess of the weight of the load being check weighed above the minimumweight limit for which the weighing system may be adjusted, into thelinear movement of a totalizing mechanism by which the average algebraicdeviation may be ascertained. Provision is preferably made forgraphically recording such average algebraic deviations, as will bedescribed.

Referring to the drawings, the invention in one of its aspectscontemplates novel check-weighing apparatus which is highly useful forany of the industrial purposes for which present checkweighing apparatusis or may be used. The present check-weighing apparatus may be used tocontrol a gross-weight weighing apparatus operatively connected tocheck-weighing mechanism, or net-weight weighing apparatus operativelyconnected to check-weighing mechanism, or a volumetric filling apparatusoperatively connected to check-weighing mechanism, and provisionis madein all of the three embodiments of the invention-described forcontrolling the op eration of the packaging machine to correct theformation of the weighed or measured loads in response to determinationsof the average algebraic deviations beyond definite amounts from apredetermined weight of a plurality or group of the check-weighed loads.

Reference is made to U. S. patent to Howard No. 2,116,895 for a completedisclosure of the grossweight weighing apparatus shown in Figs. 1 to 8.Reference is also made to the U. S. patent to Howard No. 2,364,902 for amore com le e disclosure of the net-weight weighing machine illustratedin Fig. 11; and reference is also madeto the U. S. patent to Delamere etal. No. 152 .0 0 for a complete disclosure of the volumetric fillingmachine shown in Fig. 12, and only suflicient portions of such patentedmachines have been herein illustrated as will enable the presentinvention to be understood, reference being made to such patents for amore complete disclosure thereof.

The present check-weighing apparatus of itself is, as above set forth,useful for any of the purposes for which prior check-weighing ap aratushas or may be used. In Figs. 1 and 8 we have illustrated a packagingmachine wherein the check-weighing apparatus is operatively connected toand arranged to control the loadforming mechanism of a gross-weightWeighing machine of the tvpe illustrated in the Howard Patent No.2,116,895, but it will be understood that the check-weighing apparatusmay be used alone or for controlling other machines, as for example, thenet-weight weighing machine shown in Fig. 11, and the volumetric fillingmachine shown in Fig. 12.

The present check-weighing apparatus is characterized by weighingmechanism which may comprise any usual or preferred type of Weghingmechanism and which embodies novel means for determining, eitherdirectly or indirectly, the variation or deviation of an individual loador article being check weighed from a predetermined weight. Thecheck-weighing apparatus further embodies novel means for ascertainingthe average algebraic deviation of a plurality of the weighed loads orarticles and for indicating, and preferably graphically recording, theamount of the average algebraic deviation of a group or plurality ofsuch loads or articles.

The determination of the average algebraic deviation of'the weights of aplurality of loads or particles being check weighed may be determined invarious ways, as for example, each load or article may be check Weighed,the deviat ons algebraically totalized, and the total divided by thenumber of articles or loads to give the average algebraic deviation.Another method involves the addition of the individual weights of theart cles or loads making up the group, the division of this total by thenumber of articles in this group and the subtraction of thepredetermined weight therefrom to give the average algebraic deviation.Another method involves the check weighing of each article of the group,the totalization of the weights, the division of the total by the numberof articles in the group, and the subtra tion of the predeterm ned weiht therefrom to give the average algebraic deviation. Another methodinvolves the Weighing of all of the articles or loads in the group, thesubtraction therefrom of the product of the number of articles times thepredetermined weight. and then the division of this amount by the numberof articles n the group, to give the average algebraic deviation.

When the present checl'i-weighing apparatus is embodied in or onerativelconnected to a machine whose operation it is desired to control, as forexample, milling machine of either the weighing or measuring type,provision is made for'controlling the operation of such machine inresponse to the average algebraic deviation of suc essive groups orsamples comprising a plurality of the products or loads produced by suchmachine. In practice, the samples or groups should be uniformly taken atregular intervals over a days run,

and it is preferred that the number of individual articles or loadsbeing produced by the machine to be controlled making up each samplegroup should at least equal three and preferably be five or more.

Experience has shown that this method of sampling and of controlling theoperation of a machine, and particularly a packaging machine, possessesimportant commercial utility over prior attempts which have been made tocontrol the operation of such machines by check weighing individualarticles or loads produced and then attempting to continuously correctthe machine in response to each deviation of an individual load orarticle from a predetermined weight. In many such instances theattempted corrections result in further increase in the deviationsinstead of in their reduction.

Referring now to Figs. 1 and 2, it represents the present check-weighingapparatus, and I2 represents a packaging machine illustrated in Fig. 1as comprising a gross-weight weighing machine, from which the filledpackages Hi may be delivered to the check-weighing apparatus by acontinuously moving conveyor belt E6. The packages delivered from theweighing machine l2 are arranged to be transferred by a package pusher[8 from the delivery belt I 5 onto a receiving plate 26 and into thepath of intermittently movable carrier arms 22, a plurality of which aremounted on a carrier chain 24 forming a part of the checkweighingapparatus. In operation, the package on the receiving plate 2% is movedonto the scale pan 26 of the check-weigher scale beam 28, the precedingpackage on the platform being thereby moved onto a continuously movingdischarge conveyor 3a to be delivered from the machine.

While the present check-weighing machine may be arranged to check weighsuccessive packages delivered from the weighing machine, in practice, itis referred to transfer alternate packages from the delivery belt intothe check-weighin apparatus.

The mechanism for controlling the transfer of alternate packa es fromthe delivery belt l6 onto the receiving plate 26 may include acommercially available counter 32 mounted adjacent one side of theconveyer and having an arm 34 arranged to be engaged by the packagesmoved therepast. The counter 32 is designed to be actuated to close amicro-switch 35 when the arm 34 is engaged by alternate packages. Themicro-switch 36 forms part of a circuit 38 for initiating a cycle ofoperation of the check-weighing apparatus thus effecting transfer ofalternate packages into the check weigher, the intermediate packagesbeing permitted to continue their progress along the conveyer belt pastthe package pusher i8 and out of the machine, as indicated in Fig. 1. Itwill be apparent that in practice the counter 32 may be arranged to beactuated to initiate a cycle of operation and effect the transfer of apacka e into the check weigher upon enga ement of the arm 3% by anysequence of packages, such as every third or every fifth package passingalong the conveyer, including successive packages, as desired.

As illustrated in Fig. 1, the check weigher Ill may be driven from amotor 49 belted to a olicy 42 loosely mounted on a main cam shaft -34,the pulley being formed integrally with a ratchet 46 forming the drivingmember of a one-revolution clutch. The driven member of the clutchcomprises a pawl-carrier disk 38 fast on the cam shaft and provided witha spring-pressed pawl 5!] arranged to cooperate with the ratchet toeffect rotation of the cam shaft i l when the pawl stop is withdrawn.Provision is made for controlling the operation of the one-revolutionclutch to initiate a cycle of operation of the checkweighing apparatuswhen the counter-operated micro-switch circuit 38 is closed and todiscontinue driving engagement of the clutch at the end of onerevolution. As shown in Fig. 7 a pawl stop 52 slidingly mounted in abracket 54 is arranged to normally engage the tail of the pawl 50 tomaintain the same out of driving engagement with the ratchet 46. Thepawl stop is connected by toggle links 56, 58 to the armature 00 of anelectromagnet 62 connected in the micro-switch circuit 38. In operation,when the micro-switch 36 is closed by the counter 32, the electromagnetis energized to withdraw the pawl stop 52 and permit driving engagementof the spring-pressed pawl with its ratchet. Immediately thereafter thespring turns the pawl stop into the path of the pawl to disengage thesame from the ratchet and discontinue rotation of the cam shaft at theend of one revolution.

Upon initiation of a cycle of operation of the cam shaft 44, the packagepusher I8 is arranged to be operated to transfer a package from the beltI6 onto the receiving plate 20, and as shown in Fig. 2, the packagepusher is mounted on a bar 64 supported by parallel links 66, 68 whichare rockingly supported at their lower ends in a bracket I0 attached tothe machine frame and arranged to impart a substantially straight-linemovement to the pusher. One of the links 68 is connected by a rod 12 toone arm of a cam lever I4 pivotally mounted at I6, the second arm beingprovided with a cam roll I0 cooperating with a package-pusher cam 80fast on the shaft 44. A spring 82 is connected to the lever 14 to holdthe cam roll against its cam.

The package-carrier chain 24 is then moved to advance the packages onestation of operation. As herein shown, the carrier chain is arranged torun around sprockets 64, 86 mounted on vertical shafts 68, 60respectively, journaled in the machine frame at each end of the machine.One of the shafts 68 is providedwith a bevel gear 92 arranged to meshwith a bevel gear 94 fast on a horizontal shaft 96, see Fig. 6.Provision is made for intermittently rotating the horizontal shaft 96 toeffect advancement of the carriers through cam-operated connectionsincluding a gear rack 38 arranged to mesh with a pinion I00 looselymounted on the shaft 96 and formed integrally with the driving member ofa unidirectional clutch of conventional design, indicated generally at I02, the driven member of the clutch being fast on the shaft 96. The rack93 is connected at its lower end to a cam lever I04 which is rockinglymounted at I06 and is provided with a cam roll I08 for cooperation witha cam H0 fast on the cam shaft 44. A spring H2 connected to the outerend of the lever I04 is arranged to hold the roll against its cam and toeffect downward movement of the rack. A retaining member I I4 looselycarried on the outer end of the shaft 96 is arranged to retain the rackin engagement with its pinion. In operation, when the rack 63 is movedin one direction the driving and driven members of the unidirectionalclutch I02 are in driving engagement to effect rotation of the shaft 96and advancement of the packages, and when the rack is moved in theopposite direction the clutch members are disengaged to prevent reverserotation of the shaft during the return of the rack to its initialposition. It will be observed that the carrier arms 22 are pivotallymounted on carrier members I I6 attached to the carrier chain 24, eachcarrier being provided with a roller H8 arranged to engage a stationarycam piece I20 in order to maintain the arms 22 extended substantially atright angles to the chain during the movement of the carriers. Thecarriers are urged to rock in a counterclockwise direction, viewing Fig.1, by a spring I22 connected between the carrier 22 and its supportingmember II6. In order to permit each carrier arm to be retracted or torock away from the package at the check-weighing station when the chaincomes to rest, the cam piece I20 may be provided with a low spot I24,thus preventing interference with the weighing operation.

From the description thus far it will be observed that alternates ofsuccessive filled packages delivered from a packaging machine arearranged to initiate a cycle of operation of the check weigher and thatsuch alternate packages are transferred into the check weigher and movedonto the platform 26 of the check-weighing scale beam 28. As illustratedin Figs. 2 and 3, the illustrated check-weighing unit comprises afour-bar parallel linkage wherein the upper and lower horizontal linksI26, I28 respectively comprise relatively stiif cantilever leaf springsof equal length. The springs I26, I28 are attached at one end to a rigidmember comprising a block I30 attached to the machine frame, and theother ends of the springs are secured to a second rigid member or blockI32 to which the weighing platform 26 is attached. The two rigid membersI30, I32 together with the springs I26, I28 constitute the four-barlinkage so that when a load is placed on the weighing platform 26 theweight of the load results in imparting to the platform a substantiallystraightline motion in a. vertical direction so that the load producesthe same spring deflection no matter where it is located on theplatform. The first rigid member I30, being attached to the machineframe, serves as a rigid support for the entire structure of theweighing unit, and a coil spring I34 connected between a portion of theweighing unit and a fixed portion of the machine serves to exert acounterforce upon the spring beam. The upper end of the spring I34 maybe secured to a supporting bolt I36 adjustably carried by a bracket I38attached to the machine frame, and the lower end of the spring I34 maybe secured to a bolt I40 adjustably carried by a bracket I42 projectingfrom and forming a part of the second rigid member I32 to which theweighing platform is attached. In practice, the coil spring I34 servesto counteract the weight of the platform 26 and associated parts whichare mounted upon the outer ends of the lead springs I26, I28 and may berelatively long and. of such strength as to support nearly all of theweight of the package or article being check weighed without deflectionof the leaf springs so that the deflection of the leaf springs may beproportionate to the deviation on weight above a predetermined minimumweight limit.

For example, a package weigher of 15 ounces may be used and Weightsabove 15 ounces will deflect the leaf springs proportionately to theexcess above 15 ounces. For a heavy load a heavy coil spring may beemployed, and for a light load a lighter one may be used. It ispreferred that the coil spring I34 be relatively long and large indiameter so that the counterforce will not materially increase or upsetthe desired sensitivity of the weighing unit during the elongation ofthe spring when the cantiliver leaf springs are depressed. In order todamp any undesirable vibratory oscillations of the spring beam unit 28during the weighing operation, a depending rod I43 secured to theprojection I42 of the rigid member aoaaoas I34may be provided with apiston extended into a dash pot I45, as illustrated.

From the description thus far it will be apparent that the minimumselected weight, for ex.- ample, the 15 ounces above referred to willvary according to the operating characteristicsof the filling machine,and will be selected so that deviations therefrom will be above suchminimum weight.

In practice, the stiff cantilever springs I26, I28 are selected so thatthe weighing unit has a relatively small deflection value, andsensitive, pneumatically operated gauging means, indicated generally atI44, is arranged to cooperate with the present cantilever weighing unitfor indicating or measuring the relatively small deflection of thespring beam when depressed by the load being check weighed. In general,the pneumatically operated gauging unit is of a construction as will bedescribed such that the deflection of the leaf springs increases the airpressure in the pneumatically operated unit by an amount proportionateto the deflection and consequently to the excess or deviation in weightabove the selected minimum as above described.

Provision is made as will be described for totalizing the weight inexcess of the minimum weight limit of each of the N packages in thegroup or plurality of packages comprising the sample being checkWeighed. This totalized figure will thus be N times the average weightof the group, and by utilizing a graph paper having a scale per ounceequal to N times the displacement per ounce of the totalizing device, itis possible to read directly in ounces the totalized displacement as theaverage weight of the group of N packages.

As best shown in Fig. 3, the pneumatically operated gauging unit maycomprise a conduit having a chamber I52 through which the air undersubstantial pressure may be caused to flow to be discharged through asmall discharge orifice I54 arranged to cooperate with a valve memberI56 carried by and adjustably mounted on a vertical rod I58 attached tothe projection I42 of the rigid member I62. The inlet of the conduitunit may be suplied with a regulated source of air through a flexibleair hose connection I60, and the chamber I52 is provided with arestricted throat portion I62 adjacent its inlet end arranged to offer asubstantial resistance to the flow of air therethrough. In operation,the leaf-spring weighing unit is normally maintained in a slightlyelevated or locked position with the valve member I56 spaced asufficient distance from the orifice I54 so that a relatively low airpressure is maintained in the chamber I62 during the packagemovingperiod of operation, and after a package is placed on the platform 26the beam is unlocked to permit it to perform the check-weighingoperation. Upon minute deflection of the spring bear under the influenceof the load weight in excess of the selected minimum, as for example,the 15 ounces above referred to, the valve I56 is moved toward thedischarge orifice I54 a minute amount, thereby effecting a substantialpressure increase in the chamber I52 between the discharge orifice I54and the throat portion I62, and provision is made for utilizing theincrease in pressure to effect operation of indicating mechanismgenerally referred to as I46.

As illustrated in Fig. 2, the pneumatic gauging unit I44 is connected bya flexible hose I64 to an expansible tube I66 supported at one end in anadapter collar I68fixed in a bracket I16 attached to an upstanding plateI12 forming a part of the machineframe. The expansible tube I66 isconnected at its other end to a second adapter I14 which is attached toa pawl-carrying bracket I16 in which the advancing pawl I48 is pivotallymounted at I18. The expansible tube I66 may and preferably will beprovided with a spring covering I80 tightly wound thereabout to preventlateral expansion of the tube and to force the tube to elongate when thepressure therewithin is increased thus eifecting movement of thepawl-carrying member I16 to the right viewing Fig. 2 to retract the pawlrelative to its rack I50. Upon a subsequent decrease in pressure withinthe expansible tube I66 when the leaf spring beam is again locked, thecontraction of the expansible tube permits movement of the pawl-carryingbracket I16 to the left to advance the rack I50 an increment of movementproportional to the weight of the load in excess of the selected minimumweight.

As herein shown, the pawl-carrying bracket I16 is supported uponvertical leaf springs I82 supported at their lower ends in a bracket I84attached to and extended from the frame plate I12, the pawl-carryingbracket I16 and the fixed bracket I84 together with the leaf springs I82forming a four-bar parallel linkage permitting horizontal reciprocationof the pawl-carrying member I16 with the tube I66 when the latter iselongated and contracted by the increase and decrease in air pressurerespectively. The pawlcarrying member I16 is normally urged in aposition to the left, viewing Fig. 2, by a spring I86 connected betweenthe member I16 and a stud secured to the frame plate I12, the movementto the left being limited by a stop member I 36 attached to the frameplate.

As illustrated in Figs. 2, 4, and 5, the rack I56 is slidably mounted ina groove formed in an angle bracket I90 attached to the frame plate I12,the rack being provided with a plurality of teeth for cooperation withthe advancing pawl I48. The rack I50 is normally urged to the right by aspring I92 connected between the rack and a stud fast in the anglebracket I90, the end of the rack when in its fully retracted positionbeing arranged to bear against an adjustable stop screw I94 carried bythe angle bracket I90. A holding pawl I96 pivotally mounted in a bearingblock I98 fixed to the bracket I90 serves to retain the rack in itsadvanced position until subsequently released as will be hereinafterdescribed.

The spring-beam check-weighing unit 28 is arranged to be maintained inan elevated or locked position during the package moving cycle ofoperation by a vertically reciprocal rod 266 slidingly mounted in abracket 202 attached to the machine frame, the upper end of therod-being arranged to engage a stud 204 attached to the underside of therigid member I32 of the weighing unit. The lower end of the rod 206 isbent at right angles and extended through a slot formed in the end of acam lever 206 pivotally mounted at 268, the second arm of the levercarrying a cam roll 2; cooperating with a cam 2 I 2 fast on the camshaft 44. In operation, the cam 2 I2 effects unlocking of thespring-beam unit 28 each cycle of operation after a package to be checkweighed is advanced onto the weighing platform 26, and after a sumcienttime to insure performance of the checkweighing operation the springbeam is again locked. A spring 2I4 connected to the lever 266 isarranged to hold the cam roll against its cam.

With this construction it will be seen that in .operation when thespring-beam unit 28 is released or unlocked to perform thecheck-weighing operation, the pressure in the chamber I52 is increasedby the movement of the valve I56 toward the orifice I54 when the springbeam is deflected, and consequently, the expansible tube I66 will beelongated to move the pawl-carrying bracket and its pawl I43 to theright viewing Fig. 2. The pawl I48, being pivotally mounted, rides overthe teeth of the rack I50 during this stroke and falls into the toothwhere it comes to rest. Thereafter, the spring beam 28 is again lockedthus elevating the valve I56 away from the orifice I54 to effect areduced pressure in the chamber I52 whereupon the tube I66 is contractedto permit the spring I86 to move the pawlcarrying bracket to the leftand to advance the rack I50 an increment of movement comprising ameasure of the excess in the weight of the load above the selectedminimum weight, as for example, the 15 ounces above referred to. Theholding pawl I06 retains the rack in the position to which it has beenmoved.

Provision is made in the preferred embodiment of the invention fortotalizing successive increments of movement of the rack I50 produced bythe check weighing of a predetermined number of packages in order toobtain an indication of the average algebraic deviation of the weight ofa plurality of packages from a predetermined weight, and the totalmovement of the rack from an initial position provides a measure fromwhich such average albebraic deviation may be readily determined. At thecompletion of a predetermined number of cycles of operation of the checkweigher, provision is made for recording the average algebraic deviationthus determined on a roll of graph paper. The graph paper preferably hasa central line indicating that the group of packages check weighedconforms to a predetermined weight, and any deviations from suchpredetermined weight being indicated by marks recorded on one or theother side of the central line in accordance with the position to whichthe rack I50 has been moved at the end of such predetermined number ofcycles.

As shown in Figs. 2 and 4, the recording mechanism indicated generallyat 2 I6 is supported between side plates 2I8, 220 secured to a rockerplate 222 pivotally mounted in bearing blocks 224, 226 attached to theframe plate I12 and includes a supply r011 228 of recording paper, suchas pressure-sensitive paper, which is guided over a rubber-coveredroller 230 and then downwardly onto a rewinding roller 232. The paper ispreferably arranged to be moved continuously at a relatively slow rateof speed by a small reduction gear motor 234 mounted on one side plate2I8, and which is connected to the rubber-covered roller 230, therewinding roller 232 being driven from the motor by a spring belt andpulley connection 236. As herein shown, the rack I50 is provided with apen 233 depending from its underside and extended through a clearanceslot formed in the angle bracket I90. The pen 238 is arranged tocooperate with the recording paper to mark the same, the markingoperation being effected by rocking the plate 222 on its pivots topresent the roller 230 and the paper to the pen. The rocking of theplate 222 may be effected by an electromagnet 240 mounted on thestationary bracket I84 and arranged to cooperate with an armature 242pivotally connected to the rocker plate between the edges of a slot 244formed therein as best shown in Fig. 5. The electromagnet 240 isincluded in a circuit 246 having a 10 normally open micro-switch 248provided with a spring arm 250 arranged to be engaged by acontact-closing member 252 secured to and extended laterally from a disk254 fast on a cam shaft 256, see Figs. 1 and 2.

The cam shaft 256 may be driven from the main cam shaft 44 through apinion 258 and gear 260 arranged to drive the shaft 256 at a reducedrate of speed proportional to the predetermined cycles of operation ofthe check weigher plus an aditional cycle of operation, and during suchadditional cycle the check weigher is rendered inoperative to effectmovement of the rack I50. For example, assuming that five packages areto be check weighed before the recording mechanism is to operate, themain cam shaft 44 will make six revolutions for one revolution of theshaft 255, and the contact-closing member 252 is positioned on the disk254 to close the switch 248 and energize the electromagnet 240 duringthe sixth or recording cycle.

The mechanism for rendering the check weigher inoperative to move therack I50 during the recording cycle may comprise a second spring-beamlock herein shown as comprising a vertically reciprocal rod 262slidingly supported in a bracket 263 attached to the machine frame. Theupper end of the rod 262 is arranged to engage a stud 265 adjustablysecured in the projection I42 from the second rigid member I32 of thespringbeam unit 28. The lower end of the rod is bent at right angles andextends through a slot formed in the end of a cam lever 26'! pivotallymounted at 269. The second arm of the lever 26'! is provided with a camroll 2' cooperating with a cam 273 fast on the cam shaft 256. A spring215 connected to the lever 26'! is arranged to hold the roll against itscam.

Thus, in operat on the plate 222 is rocked to present the paper to themarking pen 236 during the recording cycle whereby to provide a visualindication of the average deviation from a predetermined weight of aplurality of packages. In the event that successive packages being checkweighed are all of a substantially predeterm ned weight, successiveincrements of movement of the rack I50 will be substantially uniform sothat at the end of five cycles of operation the recording pen will bedisposed substantially in alignment with the central line 277 of therecording paper indicating that the packaging machine is functioningcorrectly to produce loads of predetermined weights. In the event thatsome or all of the packages of the group check weighed vary from thepredetermined weight but are each of a Weight above the selectedminimum, for example, above the 15 ounces above referred to, the markingpen 233 will be disposed to engage and mark the paper at a point to theright or left of the central line 271 as the case may be. Since thecontact-closing engagement with the microswitch 248 is substantiallyinstantaneous, the rocker plate 222 will be immediately returned to itsinitial position after the marking operation is performed, the returnmovement being effected by a spring 219 coiled about a screw 28Iattached to the frame plate I12. The screw is extended through anopening formed in the rocker plate, the spring being interposed betweenthe plate and the head of the screw, as shown in Fig. 5. It will beunderstood that the rate of advance of the recording paper by the motor234 may be such as to provide longitudinal spacing between successivemarkings on the paper.

After the recording operation has been performed, provision is made forreleasing the rack I66 to enable it to return to its initial position tothe right against the stop screw I94, and as herein shown a pin 283carried by one arm of a bell crank 285 is arranged to extend under boththe holding pawl I96 and the advancing pawl I48. The bell crank 285 ispivotally mounted in the stationary bearing block I98, the second arm ofthe bell crank being connected by a pin 281 to the end of an armature289 of an electromagnet 29I secured to the frame plate I12. The bellcrank is normally maintained in its inoperative position, to the leftviewing Fig. 2, by a spring 293 connected between the pin 281 and a studsecured to the frame plate I72, as shown. The electromagnet 25H formspart of a circuit 295 including a second micro-switch 29! disposedbeside the first micro-switch 248, see Fig. 1, and which is alsoprovided with a spring arm arranged'to be engaged by a secondcontact-closing member 269 carried by and laterally extended from thedisk 2-54. The second contact-closing member i9?) is spaced a shortdistance from the member IE-Z so that in operation, shortly after themarking operation is performed, the second micro-switch 291 is closed toenergize the electromagnet 29I, thus rocking the bell crank and liftingthe pawls I96, I43 out of engagement with the rack I66 whereupon thelatter is returned to its initial position by the spring I92.

In operation, the cumulated movements of the rack I56 at the end of thecheck weighing of a group sample or plurality of .packages and thegraphic recording of the average algebraic deviation of the members ofthe group will be such that the recordings on the graph paper eitherfall within or without predetermined limit lines X and Y shown in Fig.2. The limit lines X and Y may be determined in any preferred manner,and when the check weigher is to be used to control a particularpackaging or other machine, the performance of the packaging machineunder normal conditions of operation is recorded onthe graph, and aftersufi'icient groups of packages have been check weighed and the recordsrecorded so as to establish normal machine performance, the two limitpens for drawing the lines X, Y are set so as to automatically draw thelimit lines, preferably so that the control limits X, Y are slightlymore accurate than the normal machine performance. As illustrated inFigs. 1 and 4, when the rack I50 has moved so that the record of a groupsample of check weighings is disposed to the left or right of the limitlines X and Y, provision is made for detecting such a position.

For purposes of illustrating the utility of the present check weigher,the latter is illustrated herein as operatively connected with agrossweight weighing machine, or a net-weight weighing machine, or avolumetric filling machine. The detecting mechanism indicated generallyat 264 may include an underweight circuit 266 having a normally openmicro-switch 268 and an overweight circuit 210 having a normally openmicro-switch 272. Each micro-switch is adjustably mounted in abracket'Z'M attached to the side plates 2 I8, 226 of the recordingmechanism. In operation, when the plate 222 is rocked to form thegraphic record the micro-switches 268, 222 carried by the recordingmechanism are simultaneously moved toward the rack I50. As herein shown,the micro-switches are provided with switch arms 218, 266 respectivelyarranged to engage a lug 282 secured to and movable with 12 the rack toeffect closing of the respective switchesduring the recording anddetecting oper-'-' ation.

Referring now to Figs. 1 and 8, in which the check weigher I6 isillustrated as operatively connected to a gross-weight weighing machine,indicated generally at I2, in order to correct the operation of theload-forming mechanism thereof when the average algebraic deviation of asample group of loads check weighed varies'beyond a predetermined amountfrom the predetermined weight, provision is made for either increasingor decreasing by a definite increment the efiective counterweight of thescale beam 296 of the weighing machine through correcting mechanismindicated generally at 39! arranged to be actuated by the detectingmechanism 264. As illustrated in detail in Figs. 9 and 10, thecorrecting mechanism includes a coil spring 362 connected between thecounterweight end of the scale beam 236 and the upper end of a threadedstud 386 supported for vertical axial adjustment in a bracket 366attached to the frame of the gross-weight weighing machine. The threadedportion of the stud 366 is arranged to cooperate with a dual ratchetmember having integral opposed ratchets 368, 3H! supported between upperand lower bearing members of the bracket 366 and which is arranged to berotated in one direction to effect extension of the spring 382, therebyincreasing the effective counterweight when the check-weighing machinedetects an underweight condition, and to be rotated in the oppositedirection to effect contraction of the spring 362 and reduction of theeffective counterweight when the check-Weighing machine detects anoverweight condition.

As best shown in Fig. 10, the upper ratchet 308 is arranged to berotated a relatively small increment in a counterclockwise direction tocontact the spring 392 by a spring-pressed pawl 3; carried by an arm 3I6loosely journaled on an extended hub portion of the dual ratchet member,the outer end of the arm 3i6 being connected by a link 3I8 to a solenoid323 connected in the overweight circuit 2'") of the detecting mechanism264, and the lower opposed ratchet 3H] is arranged to be rotated in aclockwise direction to extend the spring 362 by a springpressed paWl 322carried by an arm32 l loosely journaled on a depending hub portion ofthe dual ratchet member, the outer end of the arm 324 being connected bya link 326 to a solenoid 328 connected in the underweight circuit 266 ofthe detecting'mechanism. The dual ratchet memher is prevented fromvertical axial displacement by engagement with the upper and lowerbearing portions'of the bracket 366, and the lower end of the springstud 366 may be provided with a lateral extension 336 having an openingarranged to receive a guide pin .332 depending from the bracket 366mprevent rotation of the stud. The pawls 3H3, 322 are normally maintainedout of engagement with their respective ratchets by a shield member 336extending from the bracket 366, and springs 336, 338 connected to thearms 316,326 are arranged to retain the latter aga-nst limiting stops366, 3 2respectively to prevent engagement of the pawls with theirrespective ratchets until one or the other of the solenoids 326, 328 isenergized by closing of the appropriate microswitch 212, or 268 in thedetectinil circuit.

From the description thus far, it will be seen that thegross-weight'weighing machine I2 may be controlled from thecheck-weighing machine in the manner described, thereby maintaining theweight deviations of the packages produced within commerciallyacceptable weight variations. The weighing machine shown in Figs. 1 and8 may comprise a weighing machine known in the trade as a two-scaleweigher and which may be of the same general type as illustrated anddescribed in the patent to Howard No. 2,116,895, to which reference maybe had for a complete description thereof. For the purposes of thepresent invention, only sufficient'portions of the complete weighingmachine have been herein illustrated as appear to be necessary for acomplete understanding of the present invention. In general, theillustrated weighing machine includes a feed hopper 359 provided withshutters 352 arranged to be opened to feed a stream of material into acarton 354 supported on the scale pan 356 of the scale beam 296, and inoperation the shutters are arranged to be closed when the carton hasreceived its weight through linkage indicated generally at 358 connectedto camoperated mechanism 369 arranged to be controlled by the scalebeam. The machine is arranged to be operated in successive cycles, acomplete cycle comprising a package-weighing cycle, and a package-movingcycle, and as herein shown the cartons may be delivered to the machineon a continuously moving inlet belt 362, successive cartons beingtransferred by a pusher 364 into the path of carrier fingers 366 carriedon a chain 368 arranged to be intermittently operated to advance thecartons one station of operation each cycle, the filled and weighedpackage being removed from the scale pan 356 and transferred to thedelivery conveyer 16, as shown in Fig. 1, to be delivered to thecheck-weighing machine 19. The above generally described mechanisms maycomprise the mechanisms illustrated in the Howard patent above referredto.

Referring now to Fig. 11, similar correcting mechanism 391, arranged tobe actuated by the check-weighing machine 19, may be embodied in anet-weight weighing machine indicated generally at 312 to cooperate withthe scale beam 310 thereof. Such machine may comprise the weighingmachine illustrated and described in the Howard Patent No. 2,364,902 towhich reference may be had for a complete description thereof. Ingeneral the illustrated net-weight weighing machine includes a feedhopper 314 having a rotatable feed drum 316 arranged to feed materialinto a receptacle 318 carried by the weighing end of the scale beam 319.The hopper 314 is provided with a gate 389 at its lower end arranged tobe held open during the weighing operation through linkage 382 includingan armature 384 arranged to cooperate with a normally energizedelectromagnet 386 to hold the gate open. The electromagnet 386 formspart of a circuit arranged to be controlled by the scale beam 319, andin operation when the scale beam makes its weight, the electromagnet isde-energized to permit closing of the gate as shown. Simultaneouslytherewith, a pawl 388 carried by the linkage 382 is engaged with aratchet 399 to discontinue rotation of the feed drum. Thereafter, theshutters 392 of the receptacle 31B are opened through cam-operatedlinkage 394 to release the weighed load which is guided through a funnel396 into a carton supported therebeneath on a belt 398. The filledcarton is then advanced along the belt 398 to be discharged onto thedelivery belt 16 and delivered into the checkweighing machine asdescribed. In the continued operation of the net-weight weighingmachine, the shutters 392 are closed, and the gate 389 may be opened andthe feed drum released by cam-operated resetting mechanism indicatedgenerally at 399 which may and preferably will comprise the mechanismshown in the Howard Patent No. 2,364,902. As illustrated in Fig. 11, thecorrecting mechanism 391 may be similar in construction and mode ofoperation to the correcting mechanism 399 above described, theunderweight and overweight solenoids 329, 321 being connected in theappropriate circuits 266, 210 of the check-weigher detecting mechanism.

Referring now to Fig. 12, in a modified form of the invention provisionis made for correcting the volume of the measuring chambers of avolumetric filler in accordance with abnormal average algebraicdeviations from a normal weight of the filled packages produced therebyas indicated by the detecting mechanism of the check weigher 19. Asherein shown, the illustrated filling machine may comprise a rotaryvolumetric filler of the general type illustrated and described in theU. S. patent to Delamere et al. No. 1,527,030 and which may comprise ahopper 499 containing a sup-ply of the material, and a series oftelescopically adjustable measuring chambers 402 cooperating therewith.The upper portion 494 of the measuring chambers may be supported by anannular flanged member 496 arranged to ride on rollers 498 carried by anadjustably supported ring 419. The lower portions 412 of the measuringchambers may be supported on a disk 414 fast on the upper end of acontinuously rotated central shaft 416, the telescoping connectionimparting rotary movement to the upper portion 494 of the chambers. Asherein shown, the chambers 492 are provided with cam-operated shutters418, and in the operation of the machine successive chambers are filledas they pass under the hopper 499 during one portion of the revolutionof the chambers during which time the shutters 418 are closed, andduring another portion of the revolution the chambers 492 pass out fromunder the hopper and the shutters are opened to release the measuredload which is guided through a funnel 429 and into acarton 422 beingmoved along in alignment therewith. The cartons may be advanced alongrails 424 by a flexible metal belt 426 having a series of blocks 421attached thereto and between which the cartons are engaged. The belt 426may cooperate with a driving pulley 428 fast on the central shaft 416,and the funnels 429 are supported in alignment with the measuringchambers 492 by brackets 439 attached to a disk 432 also fast on thecentral shaft. As herein shown, the central shaft 416 may be driventhrough a worm-gear drive 434 connected to a drive shaft 436 which maybe rotated by any usual or preferred means, such as an electric motor.In the operation of the filling machine, the cartons may be delivered tothe machine from a supply thereof, and when provided with their measuredloads, the filled cartons may be discharged from the machine anddelivered to the check weigher 18 to check the weight thereof.

Provision is made in the modified form of the invention forautomatically adjusting the upper portion 494 of the measuring chambers462 relative to the lower portion 412 in order to vary the measured loadwhen the average algebraic deviations of a group of the filled cartonsare found to vary abnormally beyond commercially acceptable limits, asdetected by the check weigher Ill, and as herein shown, the adjustingmechanism may include a plurality of screws 438 rotatably mounted in themachine frame and arranged to cooperate with a nut 448 secured in thesupporting ring Mil. The screws G38 may be connected to rotate togetherby a chain and sprocket drive 442, and one of the screws may be providedwith a bevel gear 345 arranged to mesh with a bevel gear 446 fast on ashaft 458 forming a part of the correcting'mechanism indicated generallyat 450. In operation rotation of the screws 438 in one direction willeffect elevation of the upper portion 404 of the measuring chambers toincreasethe volume of subsequent loads delivered to the cartons, androtation of the screws in the opposite direction will cause the upperportion of the chambers to be lowered into the lower portion to decreasethe volume of the chambers.

As illustrated in Figs. 13 and 14, the correcting mechanism 458, adaptedto be controlled in the manner described by the check-weighing machine'I 0, may include a pair of integral opposed ratchets 452, .53 fast onthe shaft 448 and arranged to be engaged by similar spring-pressed pawls1-54 455 to effect rotation of the shaft M8 and adjustment of thechambers 4B2 whenpermitted to do so by the check-weighing machine. Thepawls @5 3, 455 are carried by similar arms 456 pivotally mounted on theshaft 448, each arm being connected by a similar link 453 to cam levers46G pivotally mounted at 452. Each lever 450 is provided with a roller466 arranged to cooperate with similar cams 468 fast on a cam shaft M0,the arms 456 being provided with springs M2 arranged to urge the linkagedownwardly to permit the roller to follow its cam. The cam shaft 470 isarranged to be rotated from the drive shaft 436 through a chain andsprocket drive 374 and bevel gears 475.

The pawl-carrying arms 45% are normally maintained in an elevated orlocked position, as shown, by solenoid-operated latch members 478, 419arranged to engage the ends of the arms, and the pawls ar prevented fromengaging their'respective ratchets by a shield membr 580 supported fromthe machine frame. As herein shown, the lat-ch members 418, 479 arepivotally mounted at 482, Q84 and are connected by similar links 486 totheir respective solenoids 688, 490. Springs 492 cooperating withadjustable stops 49 1 are arranged to hold the latch members 478, M9 inlatched engagement with their respective arms 456, and in operation whenone or the other of the arms is released by its solenoid the arm isrocked downwardly by its spring 412 permitting the roller 486 to followits cam 88, the pawl riding oil the shield 480 and engagin with itsratchet to effect rocking of the shaft M8 and adjustment of themeasuring chambers .92 as described. The downward rocking movement ofthe arms 456 may be adjustably limited by stop screws 483.

In practice one of the solenoids 433 may be connected in the underweightcircuit 266 and is arranged to be energized to effect release ofthelatch tic when the micro-switch 268 of the detecting mechanism .265 isclosed, and the other solenoid 498 may be connected in the overweightcircuit 218 and is arranged to be energized when the micro-switch 212 ofthe detecting mechanism is closed, thus eiiecting automatic adjustmentof the measuring chambers 332 through definite increments whenthedetecting mechanism of the check weigher detects an abnormal averagealgebraic deviation of a group of packages check weighed beyondcommercially acceptable limits.

Referring now to Figs. 15, 16 and 1'7, a modified form of indicating andrecording mechanism is illustrated wherein the pneumatically operatedgauging unit its is operatively connected to a pressure-responsiveelement comprising a novel rolling tube bellows unit 5&9 arranged toactuate totalizing mechanism indicated generally at 502 and whichincludes two sets of air-brake units comprising a lower set of opposedair brakes 50 i and an upper set of opposed air brakes 556 arranged tocooperate with a slide member 568 on which a marking pen 5 l B ismounted for cooperation with the graph paper 228.

In general, provision is made in the modified form of the inventionillustrated in Fig. 15 for moving the marking pen 5H8 an increment ofmovement relative to the graph paper 228a distance proportional to theweight of the load being check weighed in excess of the selected minimumweight and for totalizing successive increments of movement of the penproduced by the check weighing of a predetermined number of packages inorder to obtain an indication of the average algebraic deviation of theWeight of a plurality of packages from a predetermined weight, the totalmovement of the pen from an initial position providing a measure fromwhich such average algebraic deviation may be readily determined.

As herein shown, the pneumatic gauging unit hit is connected by an airline M2 to a conventional pressure transmitter or booster 5M having ahigh-pressure air supply through air line 5H5, and the pressuretransmitter is connected by an air line 5 i 6 to the rolling tubebellows unit 590. As illustrated in cross section in Fig. 15, thebellows unit 599 comprises a cylindrical rubber tube 5|? attached at oneend to the bottom wall of a bored-out portion of a base member or block5H3 attached to and extended from an upstanding frame plate 5253,similar to the plate I72 in the previously described embodiment shown inFig. 2. The inner end of the tube 5!? is attached to the bottom wall ofthe block by a flanged fitting 5l9 extending over the turned-in edges ofthe tube, the stem of the flange member being extended into the blockinlet and arranged to cooperate with a threaded pipe fitting 52!connected to the air line 5E8. The tube is contained from radialexpansion by the side walls 522 of the boredout portion and the otherend of the tube is turned inwardly upon itself and secured to a movablemember comprising an adapter 524 attached to the end of a bracket 52%mounted for horizontal reciprocation, the bracket and the adapter beingconstrained to a linear motion to hold it concentric with the basemember or block EH8. The turned-in end of the tube is attached to theadapter by a screw528, the end being tucked under the head of the screw,as shown. The bracket 525 supported upon vertical leaf springs 53%attached at their lower ends to a bracket 532 secured to and extendedfrom the frame plate 52c, the horizontally reciprocal bracket 52% andthe relatively fixed bracket e32 together with the leaf springs 53dforming a fourbar parallel linkage permitting horizontal reciprocationof the bracket 52!; and the air-brake unit 5% attached thereto. In theoperation of the bellows unit 5-5 8, upon an increase in air pressure aseffected by the, pneumatic gauging unit Hi l the cylindrical tube 5|?rolls or fpeels on or from the restraining surfaces to effect movementof the bracket 526 upon which the lower air-brake unit 504 is mountedfor movement therewith. The horizontally reciprocal bracket 526 isnormally urged to the left, viewing Fig. 15, by a compression spring 534interposed between the free end of the bracket 526 and an adjustablemember 536 supported in a bracket 538 attached to the frame plate 520.The movement of the bracket 526 to the left may be adjustably limited bya stop screw 548 carried by the bracket 526 and engageable with the endof the base block 8, as illustrated. The slide member 508 is slidinglymounted in bearing arms 542, 544 attached to and extending from theframe plate 520. A bracket 546 attached .to the slide carries themarking pen 5I0 for cooperation with the graph paper 228. The slidemember 508 is initially moved to the right against a stop screw 548adjustably mounted in a bracket 550 carried by the frame plate 520.

As above described, the lower pair of opposed air brakes 504 are carriedby and movable with the horizontally reciprocal bracket 526 and arearranged to engage opposite sides of the plate 508 to effect movement ofthe plate therewith at the proper time in the cycle of operation, andthe upper pair of opposed air brakes 506 are similarly arranged toengage opposite sides of the plate to hold the plate in the position towhich it is moved by the lower pair of brake units 564. As illustratedin Fig. 16, one of the opposed upper brake units 506 is attached to theframe plate 520 and the cooperating opposing unit is attached to a bar552 supported between the bearing arms 542, 544. Each air-brake unit maybe similar in construction and mode of operation, and as herein shown,each unit may comprise a piston 554 slidingly mounted in a cylinder 556,the stem of the piston extending through an opening in an end wall ofthe cylinder for engagement with the plate 508. A sprin 558 interposedbetween the end wall and the head of the piston normally urges thepiston away from engagement with the plate 538, and the piston isarranged to be forced into engagement with the slide plate by airpressure provided through an inlet in the outer end wall of thecylinder. The outer face of the piston head may be provided with arubber sealing washer 560, as shown.

As illustrated in Fig. 16, compressed air may be supplied to the lowerpair of air brakes 504 through a flexible supply line 562 connected tothe underside of the horizontally reciprocal bracket 526 and whichcommunicates with a horizontal passageway 564 and connecting verticalpassageways 566, 568 leading to the inlets of opposed brake units 504.As herein shown, each brake inlet includes a bolt 510 extending throughan upstanding wall 572 of the bracket 526 and threadedly engaged withthe outer end wall of its cylinder, the bolt 5H] having a passagewayformed therein for communication with the cylinder chamber, and the sidewall 512 having a clearance opening for the bolt forming an annularchamher for communication with the supply passageway as clearly shown inFig. 16. The upper pair of opposed air brakes 506 may be supplied withcompressed air in a Similar manner through a supply pipe 514 having abranch 516 connected to one brake unit, and a second branch 5'18connected to the opposing brake unit. The slide plate 508 is initiallymoved to the right against its stop screw 548 by a piston and cylinderunit carried in the bearing arm 542, the piston 58!! being extended fromthe plate 508, and the cylinder 582 18 being provided with compressedair by a supply pipe 584.

In the operation of the modified form of recordin and totalizingmechanism, when the spring-beam check-weighing unit 28 is unlocked andreleased to perform the check-weighin operation, the pressure in thepneumatically operated unit I44 is increased by the movement of thevalve I56 toward the unit when the spring beam is deflected, andconsequently, the rolling bellows will be elongated to move thehorizontally reciprocal bracket 528, and the brake unit 504 carriedthereby to the right a distance proportionate to the weight of the loadbeing check weighed in eX- cess of the selected minimum weight, asindicated by the increase in pressure in the unit I44. Therolling-bellows unit 500 is constructed to quickly and accuratelyrespond to any changes in pressure by merely rolling in and out withoutany stretching of the rubber tube and without friction between theturned-in or rolled-down portions since the air pressure keeps th innersurfaces of the rolling portions separated and the tube is constrainedby the walls of the block to move in a linear path. As a res lt, arelatively great linear movement may be obtained and with minimumhysteresis to provide an extremely accurate movement of the bracket 526and its brake unit a distance directly proportionate to the pressure aplied to the-bellows.

During the movement of the horizontally reciprocal bracket 526 to theright, the air-brake unit 504 is in its open or non-engaging positionrelative to the plate 508, and the brake unit 506 is in brakingengagement with the plate to hold it stationary, and when the bracket526 comes to rest at the position to which it is moved by the increasein pressure in the bellows, the brake unit 504 engages and the brakeunit 506 disengages the plate 588. Thereafter, the spring beam 28 isagain locked, thus elevating the valve I56 away from the pneumaticallyoperated gauging unit I44 to effect a reduced pressure therein and inthe rolling bellows 500 to permit the spring 534to move thebrake-carrying bracket 526 to the left until the stop screw 540 engagesthe block 5I8, the totalizing plate 508 being moved along with thebracket 526 away from the stop screw 548. The totalizing plate is thusadvanced to the left an increment of movement comprising a measure ofthe excess of the weight of the load above the selected minimum weight.The brake unit 506 is then engaged to hold the plate 508 in its movedposition, and the brake unit 504 is disengaged in readiness for asucceeding cycle of operation.

At the completion of a predetermined number of cycles of operation ofthe check weigher, the recording paper 228 is rocked upwardlyinto'engagement with the pen 5I0 during the nonweighing or recordingcycle in a manner similar to that described in connection with theembodiment illustrated in Figs. 2 and 4 whereby to provide a visualindication of the average deviation from a predetermined weight of aplurality of packages. In practice, the pen 5I0 is initially disposed ina position to the right of the central line 211 of the graph paper, andin the event that successive packages being check weighed are all of asubstantially predetermined weight, successive increments of movement ofthe totalizing plate 508 will be substantially uniform so that at theend of a predetermined number of cycles of operation the recording penwill be disposed in substantial alignment with the central line 211indicating that the packaging mechanism is func- 19: tioning correctlyto produce loads of prede term-ined-weights- J In the event that some orall of the packages. of the group check weighed varyfrom-'the-predetermined weight but are eachof a weightabove the selectedminimum,the marking pen-5 H] will be disposed to engage and mark thepaper at a point to the right or left of the central nnez'n as the casemay be. 7

After therecording operation is performed, the totalizing platetflaisreturned to its initial positionto the--right against the stop 548 bythe pneumatically operated piston and cylinder unit 582,-asabv'edescribed, both brake units 56 5, 556 being disengaged from the plateduring the resetting operation the upperunit 5% again engaging-the-plateaftcr-ithas been moved against the-51101 548.. 1

In order to automatically. effect engagement and disengagement of thebrake units 5%,536 in the above-described sequence and in timed relationto successivecheck-weighing operations, eachair line-5E2, 5% isprovidedwith a solenoidoperated air valve 586-, 588 respectively whichmay be of any-usualor preferred commerciallv availabletype. Thesolenoid-operated valves 536, 583 areincluded in an electrical circuitprovided with micro-switches 590, 592 which are arranged to be operatedby cams 594i, 535 respectively fast on the'main cam shaft M of the checkweighing machine, as diagrammatically indicated in Fig; l7. The camg594, EQS are designedto open and close thesolenoid-operated air valves535,- 588 to sheet engagement and disengagementof the air brakes 504,1506 respectively in the'manner above described. A thirdsolenoid-operated air valve 598 is connected in theair line 584 leadingto the resetting cylinder 582, the-valve 598belng controlled bya-micro-switch 6M3 operated bv a cam 602-=fast on the camshaft 256,- thecam M32 being designed to close the switch Elli? and open the valve l538 after the predetermined number of cycles of check-weighingoperationwherebyto return thetotalizingplate5ll8 to its initialpositionagainst'the stop 5 l8-after the recording operation, was abovedescribed. Compressed air may be suppliedto the-solenoid-operated airvalves through a supplypipe 685.

While the preferred embodiment of the invention has been hereinillustrated and described it willbe understood thatthe invention may beembodied-in. other forms within the scope of the iollowingclaims- Havingthusv described the invention, what is claimed is:

1. A check-weighing machine having, in combination, v check-weighingmechanism including means for determining the'variationin theweight ofan article-from a predetermined weight, pneumatic means operativelyconnected with and controllediby said" variation-determining means forascertaining the average "algebraic deviation of aplura'lity of theweighed articles from the aforesaid predetermined weight, and indicatingmeans for indicating such average algebraic 20 means for recording suchaverage algebraic deviations on a graph.

3. A check-weighing machine having, in combination, check-Weighingmechanism including a weighing element arranged to be moved inproportion to the load being Weighed by said weighing element, a membermounted for linear movement, pneumatic connections between 'the weighingelement and said movable member for moving the member through successivecumulative increments by variations in pneumatic pressure responsive tothe excess of each" checkweighed'load in a predetermined group aboveapredetermined "minimum limit, and calibrated means cooperating with saidmovable member for indicating the .average'algebraic deviation of themembers of the group'check'weighed.

4. A check-weighingmachine having, in combination, check-weighingmechanism" including an element arranged to be moved in proportion tothe load being check'weighed, meansarrang'ed to be moved by pneumaticpressure controlled by said weighing element during each of a number ofcheck weighings an amount proportionate "to the excessof eachcheck-weighed load above'a selected minimum, and graphic recording meansfor recording the position towhich said member has been moved aiter apredetermined number of check weighings. r

' 5. A check-weighing machine as 'defined 'in claim {wherein the graphicrecording means is calibrated to graphically record the averagealgebraic deviation of a plurality of thecheckweighed articles.

6. A check-Weighing machine having, in combination, check-weighingmechanism including a weighing "element having load-supporting meansupon which the article to be check weighed maybe placed, adjustablemeans 'coopcrating with the weighing element for regulating the minimumWeight limit'above which leads supplied'to the load-supporting membercause movement of the weighing element in proportion to the excesses ofthe weighed loads above such minimum limit, and means including apneumatic circuit rendered operative by such movements of the weighingelement for determining the variation in the Weights of the articlesbeing check weighed from a predetermined weight by variations in thepneumatic pressure in said circuit, means connected with and controlledby said variation-determining means for ascertaining the averagealgebraic deviation of a plurality of said check-weighed articles fromthe aforesaid predetermined weight, and indicating means for indicatingsuch algebraic deviation.

7. A check-weighing machine as defined in claim 6 wherein an adjustablespring is utilized to adjustably determine the minimum weight limit.

8. The combination with load-forming mechanism for forming successiveloads,- of checkweighing mechanism comprising means including apneumatic circuit for determining thevariation of a pluralityofcheck-weighed loads from a predetermined Weight, means operativelyconnected with and controlled by said variationdetermining means forascertaining the algebraic average deviation of a plurality of theweighed loads from the aforesaid predetermined weight, and means forthereafter automatically increasing or decreasing theweight of aloadformed by the load-forming mechanism in the event that the above averagedeviation varies eyond predetermined amounts.

A 9. The combination ith a volumetric loadmeasuring mechanism forforming successive loads, of check-weighing mechanism comprising meansincluding a pneumatic circuit to determining the variation of aplurality checkweighed loads from a predetermined weight, meansoperatively connected with and controlled by said variation-determiningmeans for ascertaining the algebraic average deviation of a plurality orthe measured loads from the aforesaid weight, and means for thereafterautomatically increasing or decreasing the volume of a measured loadformed by the load-measuring mech anism in the event that the aboveaverage deviation varies beyond predetermined a cunts.

10. The combination with load-for ing mecln anism for forming successiveloads, of checkweighing mechanism comprising means including a pneumaticcircuit for determining the variation of a plurality of check-wei hedloads from a predetermined weight, m ans operatively connected with andcontrolled said variationdetermining means for ascertai ng the algebraicaverage deviation of a plurality of the weighed loads from the aforesaidpredetermined weight,

and means for thereafter automatically increasing or decreasing by adefinite increment the weight of a load formed by the load-formingmechanism in the event that the above average deviation varies beyondpredetei lin d amounts. 11. The combination wtih a packaging machinehaving load-forming mechanism for forming successive loads, ofcheck-weighing -r echanism comprising a Weighing element movable inproportion to excesses in the weighed loads above a predeterminedminimum limit, a pneumatically actuated member arranged to be moved byvariations in pneumatic pressure in proportion to such excesse meansrendered operative in response to the position of said movable member atthe end of a predetermined number of check-weighing operations forincreasing or decreasing by a definite increment the weight of the loadsthereafter produced by the load-forming mechanism accordingly as theposition of said movable member is above or below predeterminedpositions corresponding to permissible tolerances.

12. A check-weighing machine as defined in claim 6 wherein the means forascertaining the algebraic deviation includes a rolling bellows, a firstmember connected with the rolled end of said bellows to be movedlinearly in accordance with variations in the pneumatic pressure withinthe bellows, and a second member arranged to be successively movedthrough increments propcrtional to the distance to which the firstmember is moved.

13. A. check-weighing machine as defined in claim 6 wherein the meansfor ascertaining the algebraic deviation includes a rolling bellows, afirst member connected with the rolled ends of said bellows, a secondmember, and pneumatically operated clutch mechanism between said membersarranged to eifect movement of the second member a distance proportionalto the algebraic sum of the successive increments through which thefirst member is moved.

14. In a check-weighing machine as defined in claim 6, mechanism fortranslating minute movements of the weighing element into linearmovement of a member of the totalizing mechanism including apneumatically operated rubber tube having one end arranged to roll uponthe body of the tube and to which said member is connected.

15. In a check-weighing machine as defined in claim 6, mechanism fortranslating minute movemerits of the weighing element into linearmovement of a member of the totalizing mechanism including apneumatically operated rubber tube having one end arranged to roll uponthe body of the tube and to which said member is connected, a secondmember of the totalizing mechanism and pneumatically operated clutchmechanism connesting said first and second members to impart successivemovements in one direction to the seconcl member from successivemovements or the first member.

MAX KNOBELv THOMAS P. HOWARD.

No references cited.

